Spine-sheath polarization structures in four active galactic nuclei jets
Pushkarev, A. B.
Vetukhnovskaya, Y. N.
Yakimov, V. E.
Oxford University Press
We present the results of multifrequency (15 + 8 + 5 GHz) polarization Very Long Baseline Array (VLBA) observations of the three BL Lacertae objects 0745 + 241, 1418 + 546 and 1652 + 398 together with 5-GHz VLBI Space Observatory Programme (VSOP) observations of 1418 + 546 and 1.6- and 5-GHz VSOP observations of the blazar 1055 + 018. The jets of all these sources have polarization structure transverse to the jet axis, with the polarization E vectors aligned with the jet along the jet spine and 'sheaths' of orthogonal E vectors at one or both edges of the jet. The presence of polarization aligned with the jet near the 'spine' may indicate that the jets are associated with helical B fields that propogate outward with the jet flow; the presence of orthogonal polarization near the edges of the jet may likewise be a consequence of a helical jet B field, or may be owing to an interaction with the ambient medium on parsec scales. We have tentatively detected interknot polarization in 1055 + 018 with E aligned with the local jet direction, consistent with the possibility that the jet of this source is associated with a helical B field.
Magnetic fields , Polarization , BL Lacertae objects , General
Pushkarev, A. B., Gabuzda, D. C., Vetukhnovskaya, Y. N. and Yakimov, V. E. (2005) 'Spine–sheath polarization structures in four active galactic nuclei jets', Monthly Notices of the Royal Astronomical Society, 356(3), pp. 859-871. doi: 10.1111/j.1365-2966.2004.08535.x
© 2004, Royal Astronomical Society